若有所思

looking pensive / thoughtfully

to seem / like / as / if

to have; there is / (bound form) having; with; -ful; -ed; -al (as in 有意[you3 yi4] intentional)

somewhat / to some extent

actually / place / classifier for houses, small buildings, institutions etc / that which / particle introducing a relative clause or passive / CL:個|个[ge4]

what one thinks / person or thing that is on one's mind

to think / to consider